here's how to fix rpms dipping when coming to a stop
I feel stupid that I never tried this before. I had my idle airflow tables pretty much dead on and my ve table was damn close. But still when doing parking lot maneuvering and coming off the gas and putting the clutch in, my rpms would drop. It severely pissed me off that I could watch my rpms sit at 300 rpm and never recover while rolling and my IAC/idle trims just sat there like they didn't care. As soon as I came to a stop the IAC would jump into action, but with any speed at all it wouldn't respond. Seems to me that the idle feedback loop should kick in depending on throttle position, not speed. But enough ranting, here is the solution. You have to trick the car into using the timing to recover from rpm dips instead since the IAC won't do it for you. You can do this by making the timing at rpms below your idle (400, 600, maybe 800) higher than the timing at your idle rpm. This applies to the main and base spark tables.
For example, the stock main spark table has 19, 22, and 27 degrees of advance for 400, 600, and 800 rpm. So when you're rolling at 5 mph and the rpms dip, the lower the rpms get, the lower your timing gets. Change it to 35, 30, 25 and like magic no more dipping. Bonus: you shouldn't even need to change your idle airflow tables if you only change the timing at rpms below your idle speed.
Cliff notes: more timing below idle rpm in main and base spark tables